import cv2 as cv
img = cv.imread('../../data/messi5.jpg')
if img is None:
  print("[ERRoR] fail to read Image!!!")
  exit(0)
b= img[:,:,0]
cv.imshow("pic",b)
cv.waitKey(0)

g,r= img[:,:,1],img[:,:,2]
cv.imshow("pic",g)
cv.waitKey(0)

cv.imshow("pic",r)
cv.waitKey(0)
merge=cv.merge((b,g,r))
cv.imshow("pic",merge)
cv.waitKey(0)
cv.destroyAllWindows()